Medicare spending on breast cancer screening for women age 65 and older has jumped nearly 50 percent in recent years. But the rise in price was not associated with an improvement in the early detection of breast cancer.

Researchers at the Yale School of Medicine found that Medicare spending on breast cancer screening rose from $666 million in the years 2001-2002 to $962 million in the years 2008-2009.

So why the big increases in costs?

"The way that we screen for breast cancer has changed dramatically," explains Yale's Dr. Cary Gross, an internist and a co-author of the study. The study was published Tuesday in the Journal of The National Cancer Institute.

In the past decade, many hospitals and clinics have switched to using digital mammography machines, which, like digital cameras, provide clearer, more detailed images that are easier to store, share and enhance than their film-based counterparts. They have also adopted computer-aided detection, which can help radiologists spot tumors they might otherwise miss.

But buying new machines and training people to use them can be expensive. To offset the costs, Medicare reimburses doctors and hospitals around 50 percent more for digital mammograms than for film mammograms.

According to the Yale review of the data, the use of digital mammograms and of computer-aided detection increased nationally from around two percent to 30 percent between 2000 and 2010. As a result, the cost per screening mammogram rose from $75 to $101 during this period.

They estimated that for each Medicare recipient, the average cost of all screening-related tests, including follow-up biopsies, MRIs, and ultrasounds, increased from $76 to $112 during the time period. Almost all of that increase in cost came from digital mammography and computer-aided detection.

But switching to the more expensive technology didn't seem to help doctors spot cancer.

"The purpose of a screening test is hopefully to catch malignancy at an earlier stage when it is more treatable. But we did not see a change in the detection of early or late stage tumors," says Dr. Brigid Killelea, a breast surgeon at Yale and lead author on the study.

This study adds to the mixed report card on digital mammography since the technology first came into general use in the mid-2000s. Studies show that it can be more accurate at detecting cancer in younger women because it allows doctors to more easily identify tumors in denser breast tissue. But it is about as accurate as film scans for older women.

Radiologists argue that digital screening offers many benefits for patients, even if it doesn't always find more tumors.

"I think digital is better all around," says Dr. Daniel Kopans, a professor of radiology at Harvard Medical School, speaking on behalf of the American College of Radiology.

With digital mammography, he explains, technologists can see the images right away and can easily adjust the contrast. Patients don't have to wait for film to be developed, or submit to additional scanning if the images were overexposed or underexposed. Doctors can easily store and share images, allowing them to better track changes over time or seek the opinion of a colleague.

Kopans also points out that the Medicare reimbursement levels may not match the true costs of digital technology.

"I would urge that we look at what the real costs are rather than just saying that we shouldn't spend the money," he says.

Unfortunately, women who are concerned about their breast health — and their tax dollars — rarely have a choice of method. As of July 2014, 95 percent of mammography machines in the United States were digital.

"At this point I don't think anyone would look at this study and say they should dig the old film machines out of the closet," says Gross. Digital machines are more accurate for a subset of the population, he says, and now that they are so widespread it would be impractical for breast imaging centers to buy new film-based machines for their older patients.

But he says the study underscores the importance of fully discussing the efficacy, cost and insurance coverage of future technologies — such as 3-D mammograms, which are just starting to be introduced — before they go into common use.

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